The present invention generally relates to the installation of architectural lighting fixtures, and more particularly to the mounting or suspension of lighting fixtures from a grid ceiling system.
Heretofore, lighting fixtures have been supported below grid ceilings using cumbersome support structures that are relatively difficult and costly to install. Prior methods of support involve, for example, the use of separate support members such as angle irons or unistruts which are cut to a required length at the job site. These support members are positioned on top of or above the grid ceiling at specified fixture support locations, and then they are anchored to the building superstructure by overhead load wires. (In earthquake prone areas the load wires must, in addition to supporting a vertical load, provide lateral support.) Wherever an electrical feed is required, an electrical junction box must be installed along with the anchored support member. For this purpose commercially available mounting rails that fasten to the T-bars of the grid ceiling system are commonly used.
Mounting rails are installed across the individual grids of the ceiling's T-bar grid structure and permit the junction box to easily be located within selected grids. Sometimes a load wire is dropped directly to the mounting rail and attached by means of a wire clip, however, without independent support the load carrying capacity of such an arrangement is limited.
A need therefor exists for a comparatively simple and efficient means for supporting lighting fixtures beneath a grid ceiling system. The present invention fulfills this need by providing a load bearing mounting bracket and bracket assembly that are installed using commercially available mounting rails, that eliminate the need for separate support structures, that can satisfy most load specifications, and that offer a savings in labor and materials as compared to support systems heretofore used. The invention particularly provides the potential for substantial cost savings on large building projects involving a large number of installed lighting fixtures and fixture attachment points. The mounting bracket and bracket assembly of the invention are readily adapted for use at both electrical feed and non-feed locations, and can be used to accommodate different structural environments and load wire configurations.